freebsd-dev/stand/i386/libi386/multiboot_tramp.S
2017-11-14 23:02:19 +00:00

52 lines
2.1 KiB
ArmAsm

/*-
* Copyright (c) 2014 Roger Pau Monné <royger@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#define ASM_FILE
#include "multiboot.h"
/*
* The multiboot specification requires the executable to be launched
* with %cs set to a flat read/execute segment with offset 0 and limit
* 0xFFFFFFFF, and the rest of the segment registers (%ds, %es, %fs,
* %gs, %ss) to flat read/write segments with the same offset and limit.
* This is already done by the BTX code before calling multiboot_tramp,
* so there is no need to do anything here.
*/
.globl multiboot_tramp
multiboot_tramp:
/* Be sure that interrupts are disabled. */
cli
movl $MULTIBOOT_BOOTLOADER_MAGIC, %eax
/* Get the entry point and address of the multiboot_info parameter. */
movl 8(%esp), %ebx
movl 4(%esp), %ecx
call *%ecx